Formaldehyde exposure linked with ALS in U.S. study

By Julie Steenhuysen

CHICAGO (Reuters) - Exposure to the widely used chemical formaldehyde may raise one's risk of getting amyotrophic lateral sclerosis (ALS), or Lou Gehrig's disease, U.S. researchers said on Wednesday.

A large study examining a possible association between ALS and 12 types of chemicals turned up the link, which researchers said needs to be confirmed in other studies.

While they found no significant link between ALS and most chemicals, including pesticides and herbicides, they found people who had been regularly exposed to formaldehyde were 34 percent more likely to develop ALS.

"We really went into it interested in the pesticide and herbicide question," said Marc Weisskopf, a researcher at the Harvard School of Public Health who presented his findings at a meeting of the American Academy of Neurology in Chicago.

"It has not been previously looked at in ALS," he said.

The study involved more than 1,100 people enrolled in a cancer prevention study who died of ALS. They were asked about their exposure to formaldehyde and other chemicals in 1982, and then followed for 15 years.

Weisskopf said certain jobs seemed to have a much higher risk. They included beautician, pharmacist, mortician, chemist, lab technician, dentist, fireman, photographer, printer, nurse, doctor and veterinarian.

"People in those jobs had about a 30 percent higher rate of ALS," he said.

Weisskopf said the finding could still just be chance, but he did find that the more exposure to the chemical people reported, the more likely they were to develop ALS, which strengthened the association.

"Ideally, we would like to see people start looking at this and see whether the finding holds up in other settings," Weisskopf said in a telephone interview.

Formaldehyde is used in particle board and other wood products, permanent press fabrics, glues and household products such as cosmetics and shampoo. It is also used to preserve tissue in laboratories and mortuaries, and as a disinfectant.

In 1987, it was classified as a probable human carcinogen at high exposure levels.

ALS progressively kills nerve cells that control muscle movements known as motor neurons in the brain and spinal cord. It is sometimes called Lou Gehrig's disease for taking the life of the famous New York Yankees baseball player in 1941.

About 5,600 people in the United States are diagnosed with ALS each year, according to the ALS Association.

(Editing by Will Dunham)